Ion implantation is a physical process that is employed in semiconductor apparatus fabrication to selectively implant dopants into a semiconductor workpiece and/or wafer. Ion implantation can be performed in various ways in order to obtain a particular characteristic on or within a substrate (e.g., such as limiting a diffusivity of a dielectric layer on the substrate by implanting a specific type of ion).
In a typical serial implantation process an ion beam may either be scanned across a single axis of a workpiece moving in the orthogonal direction, or alternatively a workpiece may be moved along a pair of orthogonal axes with respect to a stationary ion beam.
FIG. 1 illustrates a plan view of an exemplary ion beam path 100 scanned along orthogonal axes, viewed from the trajectory of the ion beam, as the ion beam 106 scans over a workpiece 102 during an implantation process. In particular, during the implantation process the ion beam 106 may be focused at a spot while a moveable stage 108, holding the workpiece, is operable to translate the workpiece 102 along a path 104 having a fast scan axis 110 and a generally orthogonal slow scan axis 112. In general, a speed that a workpiece is moved along the fast scan axis 110 (also referred to as the “fast scan direction”) is significantly faster than a speed that the workpiece is moved along the slow scan axis 112 (also referred to as the “slow scan direction”).